1. Field of the Invention
The present invention relates to a cooking stove comprising heating means, and in particular, to a cooking stove comprising an electrical capacitance touch switch allowing a user to instruct the heating means to be actuated.
2. Description of the Related Art
A cooking stove has hitherto been known which has heating means such as an induction heating coil accommodated below a top plate made of heat resistant glass, to heat a material to be cooked placed on the top plate, wherein an electrical capacitance touch switch constitutes an operation switch for instructing the heating means to be actuated (see, for example, Japanese Patent Laid-Open No. 2003-272816).
The top plate can be flat by employing the electrical capacitance touch switch as an operation switch as described above. This prevents the operation switch from obstructing cooking, thus allowing a user to use the cooking stove more easily and efficiently.
However, if the electrical capacitance touch switch is employed as an operation switch for instructing the heating means to be actuated, it is not necessary to operate the switch with a somewhat strong force as in the case of a pushbutton switch or a rotary switch. Thus, even when a child, who cannot exert a strong force, plays with or inadvertently touches the touch switch for instructing the heating means to be actuated, the touch switch disadvantageously changes from a non-sensing state to a sensing state to start actuating the heating means.
Here, the electrical capacitance touch switch changes from the non-sensing state to the sensing state when an electrostatic object having a capacitance exceeding a predetermined threshold value contacts or approaches a touch area. Thus, the threshold value may be set at a level such that the touch switch does not change from the non-sensing state to the sensing state when a finger of a child, who has a lower capacitance, touches the touch area and changes from the non-sensing state to the sensing state only when an adult's finger, which has a higher capacitance than the child's, contacts the touch area.
However, when the single touch switch is used to instruct the heating means to be actuated and stopped, if the sensitivity of the touch switch is lowered as described above, a child's operation of the touch switch is not accepted even when the touch switch is operated while the heating means is in operation to stop the heating means. Consequently, it is impossible to ask the child to stop the heating means.
It is thus an object of the present invention to provide a cooking stove comprising a touch switch that can prohibit a child from instructing the heating means to be actuated, while permitting a child to instruct the heating means to be stopped.